The present invention relates to a number assignment module setting system for a portable telephone set using a number assignment module adapter and, more particularly, to setting of a mode for inputting a number assignment module.
The number assignment module (to be referred to as NAM hereinafter) of a portable telephone set will be described first. The NAM is information, such as the telephone number, country code, password, and the like of a portable telephone set, required to use the portable telephone set. In general, when a NAM is to be written in a portable telephone set, a NAM setting adapter is connected to the portable telephone set, and the portable telephone set is set in a special mode (to be referred to as a programming mode hereinafter) different from a normal operation mode. A mode setting method of setting a portable telephone set in the programming mode will be described below. Note that a NAM is set by using the NAM adapter because it is required that a NAM setting operation be performed by maintenance personnel but not by an end user.
A conventional programming mode setting operation of a portable telephone set will be described next. In the conventional programming mode setting method, a NAM setting adapter is connected to a portable telephone set, which has a function of setting a NAM in cooperation with the NAM setting adapter, through an I/O interface section, a connector, and a cable. The power key is then depressed to supply power from the portable telephone set. In this case, the NAM setting adapter connected to the portable telephone set outputs 1-byte mode request data for requesting a shift to the programming mode to the portable telephone set.
As described above, the conventional NAM setting adapter has a function of outputting pre-stored 1-byte mode request data upon reception of power through the portable telephone set. Upon reception of the 1-byte data from the I/O interface section immediately after the power key is turned on, the portable telephone set performs collation/analysis to check whether the 1-byte data is mode request data from the NAM setting adapter. If the 1-byte data coincides with the mode request data, a predetermined specific key input operation is subsequently performed to shift the portable telephone set to the programming mode. A NAM can be set by operating the keys of the portable telephone set only in this programming mode.
The conventional portable telephone set also has a function of prohibiting a shift to the programming mode even by performing the specific key input operation if the 1-byte data, received immediately after the power is turned on, does not coincide with the mode request data for requesting a shift to the programming mode, or if no data is received when the power key of the portable telephone set is turned on.
In the above-described conventional number assignment module setting system for a portable telephone set, the NAM setting adapter outputs 1-byte data to the portable telephone set upon reception of power through the portable telephone set. The portable telephone set performs collation/analysis to check whether the 1-byte data is mode request data for requesting a shift to the programming mode. If the two data coincide with each other, a predetermined specific key input operation is performed by using the portable telephone set. For this reason, if an end user illegally obtains or copies the NAM setting adapter, the telephone number and the password can be arbitrarily rewritten, thus allowing illegal use of the portable telephone set.